The present invention relates to various embodiments of a system, controller and method for testing a solenoid. The solenoid may be one of a plurality of solenoids in an electropneumatic valve on a commercial vehicle. The electropneumatic valve includes at least one solenoid that responds to an electronic control signal by opening or closing a passage in the valve. Due to the high operating current requirements for solenoids, the control voltage for the electropneumatic valve operation is typically provided from a vehicle's battery through a controller. The electropneumatic valve has a voltage rating and the voltage rating indicates that the electropneumatic valve is compatible with a particular battery voltage value.
Commercial vehicles, such as trucks or tractors, may be equipped with a twelve volt battery system, a twenty-four volt battery system or another battery system. The battery system installed on the commercial vehicle depends on the commercial vehicle application and expected power usage.
Commercial vehicles equipped with an antilock braking system or an electronic stability control system typically have at least four electropneumatic valves connected to a braking system controller. The voltage rating of each electropneumatic valve is selected to be compatible with the battery system on the commercial vehicle in order to operate properly. In general, electropneumatic valves are packaged in nearly identical housings for ease in installation and, in most cases, the voltage rating of each electropneumatic valve can only be determined by the markings on a label. If the voltage rating of the electropneumatic valve is different than the voltage rating of the battery system on the commercial vehicle, the electropneumatic valve may not work or may partially actuate. During an antilock brake or automated brake application, the braking performance may be degraded.
Even if the electropneumatic valve has the same voltage rating as the commercial vehicle, the solenoids in the electropneumatic valve may incur a short circuit or an open circuit state due to faulty installation or extended use. The solenoid resistance may also degrade over time or be out of range due to a manufacturing defect or environmental factors. If the solenoid resistance is not within the specified values, the electropneumatic valve may not work or may partially actuate. During an antilock brake or automated brake application, the braking performance may be degraded.
The present invention provides a new system, controller and method which address the above referenced problems.